Adjustable tuning mechanism



April s, 194.1.

haal.

' J. J. HOBING 2.237,48?

ADJUSTABLE TUNING AMECHANISM Filed Hay 23, 1939 Jul/us' dHoa/fv'e.

ATTORNEYS,

Patented Apr. 8, -1941 ADJUSTABLE TUNING MECHANISM Julius J. Hobing, Cincinnati, Ollio, assigner to The' Crosley Corporation, Cincinnati, 0hio,.a

corporation of Ohio -Application May 23, 1939, Serial No. 275,232

1 Claims.

My invention relates to so-called automatic tuning devices for radio sets which comprise a series of manually operable elements each of which is capable, when actuated, of tuning the radio set to a station for which the particular element and its associated mechanism has been adjusted. With the understanding that it is not limited thereto and that with modification the principles of my invention may be applied to other structures, I shall describe my invention in an exemplary embodiment as applied to a type of tuning mechanism such as that devised by l-lovvard J. Tyzzer and illustrated in his Patent lilo. 2,222,7t9 filed February 24, 1938 and issued November 26, 1940. I-liere a pivoted plate is coupled to a condenser gang, and a series of plungers are provided moving transversely to and through the axis of the plate. 'I'he plungers bear means for moving the plate to diierent positions, and these means are adjustable on the plungers. 'They are, in fact, members pivoted to the plungers, having means for contacting the plate on each side of its axis so as to give two-way location, and having frlctional means for haring the position of the pivoted members on the plungers.

ln effecting a setting of the elements of the lfyzser structure, a plunger is depressed, a set screw on the plunger which affects the frictional locir aforesaid is loosened, and the radio set is manually turned to the desired station. 'l'his causes the plate to move the member pivoted to the plunger to a position appropriate to the se iected station, in which position it is then locired by tightening the set screw. Thereafter,` when 'the plunger is actuated the member will move shaft to the hand tuning device of the radio set.A

When these connections were effected (as could be done by the operator at will by exerting somewhatmore than normal force on a control button for each plunger) the operation of tuning the radio set by hand served to effect a new setting of the positioning member on the plunger.

It is an object of my invention also to improve the convenience of the setting operation, but to do so with mechanism which is much simpler and much less expensive.

It is my object to secure a further convenience ln that the actuation of any tuning element can be made not only to permit a variation of the settimng but actually to eiect the variation of the sett g.

Thus it is my object to provide a structure in which the actuation of a plunger' and the adjustment of the setting for that plunger can be accomplished by manual movement of a single element. This renders it unnecessary both to actuate a plunger and at the same time to tune the set by hand. By the same token I provide one-handed operation both for automatic tuning and for setting.

In my structure, where desired, each plunger becomes a micrometer or vernier tuning device for the radio set, so that it is even possible to do away with the usual manual tuning means under some circumstances. However, the usual manual tuning means will ordinarily be retained to avoid disturbing the setting of the plungers; but the manual tuning means may Well be an extra plungergdevice of the form hereinafter described.

In my structure a plunger may be depressed, and then a correction of its setting made or an entirely new setting effected all with one hand and without visual inspection. The convenience of this in ordinary operation and the vital character of it from the safety standpoint in automotive radio worlr will at oncebe appreciated.

'lhese and other objects of my invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain con-- struction and arrangement of parts of which l shall now describe the aforesaid exemplary em bodiment.

Reference is made to the drawing wherein*- Figure 1 is a plan view with parts in section` of one form of my apparatus.

Fig. 2 is a vertical sectional view thereof taken along the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of one of the moving members which form the positioning structure for my plungers.

Fig. 4 is a perspective view of the other of the moving members.

Fig. 5 is a perspective view of the plunger body with the positioning devices removed.

Fig. `6 is an elevational view of part of my apparatus with the extending ends of the plung-l ers in section, the section being taken along the line 6-6 of Fig. 2.

I have shown in the figures a, base I having front and rear walls 3 and 4 and side walls 5 and 1. A gang condenser indicated generally at 8 is shown mounted on this base. A plate 3, which may be similar to the plates employed by Tyzzer and by Manning and Depweg is pivoted between the end walls 5 and 1, as at I0. The plate bears a gear segment II which meshes with a gear I2 on the shaft I3 of the condenser gang. The gear I2 may be and preferably is formed of two spring pressed portions, a structure common in this art for the purpose of taking up lost motion. An ordinary dial arrangement and/or a manual tuning apparatus, both common in this art, may be attached to the projecting end of the shaft I3. It will be evident from the structure thus far described that a rotary motion of the plate 9 about its pivot I0 will operate to rotate the condenser shaft whereby to tune the condenser gang.

Journaled in the front and rear walls 3 and 4 of the base I provide a series of plungers which will now be described in detail. Each plunger comprises a body such as that shown in Fig. 5. The body is wider at its front portion than elsewhere and its edges are turned over at I4 and I5 to provide a slideway for a purpose hereinafter to be described.l The body I6 has a tail portion I1 which is journaled in the rear wall 4 of the base in a slot provided for the purpose. A cotter pin I8 beyond the rear Wall 4 may be provided in the tail to limit the forward movement of the plunger. The portions I4 and I5 of the plunger body are journaled in the front wall 3 in a suitably shaped slot therein as shown most clearly in Fig. 6, the slot having a sidewise enlargement I9 to accommodate the structure hereinafter to be described. Intermediate its length the plunger is provided with a bracket of angular shape having a portion riveted or otherwise attached to the plunger and a portion upstanding therefrom in a plane transverse to the longitudinal axis lof the plunger. This upstanding portion is perforated as at 2I to provide a bearing for an end of a rotatable shaft to be described. The forward end of the plunger is bent over as at 22 to form an ear or bracket parallel to but interspaced from the upstanding portion of the bracket; 20. The ear 22 is perforated as at 23 to accept the shaft. Finally the plunger may be provided with a downwardly extending ear 2@ perforated as at 25. The end of a coiled spring 25 may be engaged in this perforation and may also be engaged in a perforation in the front wall 3 of the base for the purpose of drawing the plunger forwardly except when actuated by the fingers.

rI'he slideway Id, I5 on the plunger accepts the members shown in Figs. 3 and 4 in superposed relationship. The member 21 of Fig. 3 has a body adapted to slide in the slideway. Extending from this body in one direction is a projection 23 having a rounded end and adapted to engage the plate 3. Centrally I strike-up from the body 21 an ear 29 which is perforated as at 3E and is threaded. The member of Fig. 4 has a body 3| with a projection 32 at one end thereof extezding in a direction opposite to the direction in which the projection 28 of the body 21 extends. From the body BI I also strike up an ear 33 having a perforation 34 which is threaded. l have shown exemplary shapes of the bodies 21 and 3i, but these may be considerably varied without affecting their operation. Also these bodies may be slidably guided in the plunger for movement along the longitudinal axis of the plunger otherwise than by means of guides I4 and I5, as will be evident. The structure which I am describing is an exemplary structure.

When the body 3l is superposed upon the body 21 in the guideways I4 and I5 as shown clearly in Figs. 1, 2 and 6, the perforation 2| in the ear 20, the perforation 30 in the ear 29 on the body 21, the perforation 34 in the ear 33 on the body 3l, and the perforation 23 in the ear 22 on the plunger are all in alignment. The shaft which has been referred to above is indicated at 35 and passes through these perforations. It is reduced as at 36 and is journaled in the ear 20, the reduced portion forming a shoulder, holding the shaft from movement to the left. An enlarged end 31 of the shaft is journaled in the perforation 23 of the ear 22 and is held from movement to the right by means of a collar 38 or otherwise, as may be desired. The portions of the shaft which pass through the ears 29 and 33 are respectively provided with right and left hand threads, the perforations 30 and 34 being similarly threaded.

It will now be evident that in the specific structure the result of turning the shaft 34 in its bearings will be to move the bodies 3| and 21 in the slideways I4, I5 in opposite directions but equal distances.

It Will be noted in Fig. 2 that the engagement means 28 and 32 on the bodies 21 and 3l respectively are oppositely disposed, one on each side of the plunger, and also that they are disposed in such a way as to contact the plate 9 respectively on 'opposite sides of the axis of the plate. The plate is shown as centrally perforated to accept the tail I1 of the plunger. In practice the contacting portions 28 and 32 of the two movable bodies on my plunger act upon the plate like the contacting means of the pivoted element on the plungers of Tyzzer, as set forth in his application' referred to above, and it will further be clear that as the contacting means 28 and 32 are moved equally in opposite directions the same effect will be obtained as though Tyzzers pivoted positioning member were adjusted to a new position on Tyzzers plunger. So long as the shaft 35 is not rotated the bodies 21 and 3| are in effect locked in position on the plunger Id, and are not liable to change of position. The extension 31 on the shaft 35 r'nay pass through the front wall 33 of a radio set and may be provided with on actuating button or knob 40. When this knob is depressed by the fingers, the plate 3 will be moved by the plunger to a position corresponding to the setting of the contacting members 23 and 32. Should this setting, however, not be accurate for the station desired, it may readily be adjusted by merely twisting the knob liti, which moves the contacting points 28 and 32 relatively to each other. In the same way the particular plunger though accurately adjusted for a particular station may be readily readjusted to a different station.

It is within the purview of my invention to provide but one moving contacting member, say the member 32 on the body 3i, and provide the other contacting member 28 iixedly upon or integral with the body I6 of the plunger. In this event I do not need to provide a right and left hand screw but a singly threaded shaft passing through a threaded ear on the moving ear will serve the purpose. The advantage, however, of providing two moving bodies. moving equally in opposite directions as the shaft is turned is this: That by so doing the distance to which it is nec. essary to move the plunger in tuning the radio set remains fixed, whereas otherwise it would vary slightly. 1

` I have described an exemplary embodiment of my invention, which, however, is not the only embodiment in which it finds utility. It will be readily apparent that it is not necessary that my plungers be operated by the finger or that a finger'knob 40 be adapted to the end of the shaft 35. I may actuate my plungers by means of solenoids in the manner shown in the Man-- ning 8a Depweg patent hereinabove mentioned. Or my plungers may be otherwise actuated, and the end of the shaft 35 cut 4oif short and slotted for engagement by a screw driver as shown in the dotted lines at 4I in Fig. 2. Even where this is done I gain this advantage in my structure: That the shaft 35 regarded as an adjustment means merely, actually effects the adjustment when turned rather than merely releasing the lock on 'theipsitionihg member which must be otherwise adjusted, as by tuning, the set with the usual hand control.

Modifications may be made in my invention without departing Vfrom the spirit of it.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent:

l. In a device of the character described, a plunger, a pair of longitudinally slidable elements mounted on said plunger, a shaft journaled on said plunger and having threaded engagement respectively with said longitudinally slidable members, the said engagement being respectively by right and left hand threads whereby rotation of said shaft will move said longitudinally slidable members equally and oppositely with respect to said plunger.

2. In a device of the character described, a

plunger, a pair of longitudinally slidable elements mounted on said plunger, a shaft journaled on said plunger and having threaded engagement respectively with" said longitudinally slidable members, the said engagement being respectively by right and left hand threads whereby rotation of said shaft will move said longitudinally slidable members equally and oppositely with respect to said plunger, said longitudinally slidable members having oppositely extending contacting portions for positioning a positionable element.

3. In a device of the character described, an element pivoted for rotation on an axis and a plunger having means for positioning said element, said plunger being mounted for motion transversely to said axis and/Xbearing thereon oppositely longitudinally slidable members bearing respectively said contacting means, a shaft journaled on said plunger and having respectively right hand and left hand threaded engagement with said members whereby upon rotation of said shaft said members are moved relatively to each other equally and oppositely, whereby to adjust said contacting members.

4. In a device of the character described, an element pivoted for rotation on an axis and 'a plunger having contacting means for positioning said element, said plunger being mounted for motion transversely to said axis and bearing thereon oppositely longitudinally slidable members bearing respectively said contacting means, a shaft journaled on said plunger and having respectively right hand and left hand threaded engagement with' said members whereby upon rotation of said shaft said members are moved relatively'w to each other equally and oppositely, whereby to adjust said'contacting members, and operating means on said shaft whereby said shaft may be rotated and whereby said plunger may be moved longitudinally.

JULIUS J. HOBING. 

